PHOENIX -- The results of a surprising new poll in the U.S. Senate race were released Wednesday showing Democrat Richard Carmona beating his Republican rival.

The survey, which was conducted by a GOP-friendly firm, shows Carmona holding a 5-point edge over Jeff Flake.

Heading into the race, Flake was considered the heavy favorite to win in a state where Republicans hold a comfortable registration advantage over Democrats.

Officials with Flake's campaign declined to comment on the poll. But Flake's spokesman, Andrew Wilder, said, "We've always known this race is going to be a close one. That's why Jeff Flake is working hard to gain the trust of voters."

But a spokesman for Carmona's camp said they were pleased.

"We don't put too much weight in any poll, but this confirms what our campaign has been saying all along," said spokesman Andy Barr. "Dr. Carmona is a unique candidate with a background that appeals to Independents, Republicans, and Democrats."

Specifically, the numbers show Carmona with 44 percent and Flake with 39. But 16 percent of those questioned said they were undecided.

Of the 620 voters questioned, 37 percent were Republican, 34 percent were Democrat, and 29 percent were independent. The poll had a margin of error of 4 points.

The authors of the poll did not want to be identified because they were not authorized to release the details.

This comes on the heels of another survey released a couple of weeks ago showing Carmona trailing Flake by a single point.

More importantly for Carmona, the latest survey results continue a trend.

According to Talking Points Memo's Polltracker, Carmona has been steadily gaining on Flake since June. Although Flake was still battling a primary opponent at the time, it appeared he would easily win the nomination.